<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .container {
            /* width: 1000px; */
            margin: 0 auto;
        }
        .container ul {
            display: flex;
            flex-flow: row wrap;
        }
        .container ul li {
            float: left;
            /* flex:1; */
            height: 30px;
            text-align: center;
            background-color: pink;
            border: .5px solid rgb(63, 128, 172);
            list-style: none;
            box-sizing: border-box;
        }
        
        @media screen and (max-width: 767px) {
            .container {
                width: 100%;   
            }
            .container ul li {
                flex: 50%;
                /* width: 50%; */     
            }
        }
        @media screen and (min-width: 768px) {
            .container {
                width: 750px;   
            }
            .container ul li {
                /* flex: 33.33%; */
                width: 33.33%;
            }
        }
        @media screen and (min-width: 992px) {
            .container {
                width: 900px;   
            }
            .container ul li {
                flex: 25%;
                /* width: 25%;  */
            }
        }
        @media screen and (min-width: 1300px) {
            .container {
                width: 1200px;   
            }
            .container ul li {
                flex: 1;

            }
        }
    </style>
</head>
<body>
    <div class="container">
        <ul>
            <li>导航</li>
            <li>导航</li>
            <li>导航</li>
            <li>导航</li>
            <li>导航</li>
            <li>导航</li>
            <li>导航</li>
            <li>导航</li>
        </ul>
    </div>
   
</body>
</html>